Method of and apparatus for coating metal articles



Dec. 10,1929. 7 D. G. GRISWOLD 1,739,482

METHOD ,OF AND APPARATUs'FoR COATING METAL ARTI LES Original F led Dec. 29 2 11 Sheets-Sheet 1 iQawvn/ A TTURNIE YS Dec. 10, 1929. D. s. GRISWOLD Ii339,482;

I METHOD OF AND AFPARATUS'FOR COATING METAL ARTICLES Original Filed Dec. 29. 1922 1 Sheets$hee 2 [MENTOR fimwam 1 k w 2n ATTORNEY Dec. 10, 1929. I p. G. GRISWOLD 1,739,482

METHOD-Of AND APPARATUS FOR COATING METAL ARTICLES Original Filed Dec. 29. 1922 11 Sheets-Sheet 5 INVENTOR A TTORWEYS Dec. 10, 1929. D. G. GRISWOLD 1,739,482

I METHOD OF AND APPARATUS FOR. COATING METAL ARTICLES Original Filed Dec. 29, 1922v 11 Sheets-Shegt 4 W w w a 5 3/ M 31 Y Z9 79 i 8 1-1 Z W i I g UK 1 l g r E 1 [K I 1 W l 1 1 :1 1 7 U114 11 Q r 7-7 1 22 i; 1 0

1 1 .76 I a I 7 3y 0 J 54'. 5a" 3% 54L 2 25 5,26 27 M/VE/VTOI? A TTOR/VEYS Dec, 10, 1929. v D. G. GRISWOLD 1,739,482

METHODLOF AND APPARATUS FOR COATING METAL ARTICLES Original Filed Dec'. 29. 1922 11 sheets-sheet 5 ili! lllllllllll A TTORNEYS Dec. 10, 1929., D. e, GRISWOLD 1,739,482

METHOD OF AND APPARATUS FOR COATING METAL ARTICLES Orig inal Filed Dec. 29. 1922 11 Sheets-Sheet 6 Dec. 10, 1929. D. G. GRISWOLD METHOD 'AND APPARATUS FOR C OATING METAL ARTICLES bri inal Filed Dec. 29, 1922 s ets-Sneak? I ATTORNEYS.

Dec. 10,1929. D. G. GRISWOLD, I I 1,739,432

METHOD OF AND APPARATUS FORCOATING METAL ARTICLES 4 Original Filed Dec. 29 1922 11 Sheets-Sheet 8 4 INVENTOI? 4 TTORNE Y8 Dec. 1!), 3929. D. G. GRISWQLD 1,739,432

METHOD OF AND AP PARATUS FOR COATING METAL ARTICLES Original Filed Dec 29. 1922 11 Sheets-Sheet 9 YIIIIIIIIIIIIYIIII/Il IiIINIIIll-II! V I v INVE/VTUR 0W5). /z'mwfd v A TTORNEYS Dec. 10, l929. GRISWOLD 1,739,482

METHOD OF AND APPARATUS FOR COATING METAL ARTICLES Original Filed Dec. 29. 1922 11 Sheets-Sheet l0 al/swam )1 TTORIVE 25 Dec. 10, 1929. I Q g swo p 1,739,482

METHOD Of AND APPARATUS FOR COATING METAL ARTICLES Original Filed Dec. 29. 1922 11 Sheets-Sheet l1 INVENTOR A rromv rs Patented Dec. 10, 1929 umrao STATES PATENT OFFICE DARWIN G. GRISWOLLD, or wnrrmoronn, ooivniac'rrcu'r, ASSIGNOR To B. WALLACE &

sons MFG. oo.-, or WALLINGFORD, comvnc'rrcur, A conrormrron or connrzcrrr- GUT METHOD OF APPARATUS FOR COATING METAL ARTICLES Applicationfiled December 29, 1922, SeriaI-No. 609,551, Renewed April 12, 1929.

My invention relates to a machine for, and methods of, automatically tinning articles, such as spoons, forks and like, although its field, of usefulness is not limited to the tinning only of articles. v I

The object of the invention is to provide a means and method by which such articles may be rapidly and thoroughly coated, and by which savings are effected in labor and material. Many other advantages will appear to the mechanic skilled in this art from a reading of the following description and an Figure 1 is a side elevation of what I may term a work carrier, the same being shown on a relatively enlarged scale.

Figure 5 is, in the main, a vertical section of the parts shown in Figure 4:.

Figure 6 is a relatively enlarged detail view in section of certain parts of the work carrier.

Figure 7 is a diagrammatic view, illustrative of different positions of a work carrier relatively to certain co-related parts of the machine. Figure 8 is an extension view of Figure 7.

Figure 9 is a plan view of certain parts of the driving mechanism.

Figure 10 is a side elevation of certain portions of the work carrier and co-related parts.

Figure 11 is a front elevation of certain of the parts shown in Figure 10.

Figure 12 is a relatively enlarged perspective view "of the lower end of the work carrier illustrating the work gripping means.

Figure 13 is a plan view of certain parts 'of the spindle and work spinning apparatus.

Figure 14 is a side elevation of the same parts, said view being partly in section.

Figure 15 is a diagrammatic view of the constant level mechanism associated with the machine. I

Figure 16 is a plan view of certain details referred to hereinafter as the aligning mechnism. Y

Figure 17 is a side elevation of the parts Figure 20 is a similar view of a reservoir taken in a different plane. v

Figure 21 is a horizontal sectional view of the reservoir shown in Fig. l9, and illustrating insulating pads in place.

Figure 22 is a relatively enlarged sectional view taken substantially in the plane of the line 2222 of Fig. 21, one pad being omitted.

I have disclosed herein, the machine in its preferred form only, and as adapted to apply a coating of tin to such articles as spoons and forks, accordingly it should be understood that I contemplate that' many changes may be made without departing from the real spirit and scope of my invention.

1-1 represent suitable pedestal supports for the machine, 2 is a casing in the upper part of which is mounted a reservoir 3 in the form of a metal trough of semicircular form. Thistrough is provided to contain the coating material which is to be applied to the articles. In the lower part of the reservoir are heating units 41, each of which, in the form shown, is cup shaped and is surrounded be connected with a source of electrical energy for the purpose of supplying heat to melt, and to keep in the proper molten state, the

,tinning material with which the articles are 'with electrical resistance wire 5, which may scribed. Directly above the cam ring 7 is rotatably mounted a wheel 8 for supporting the so-called work carriers,"s aid wheel being rotated by any suitable means, such as a system of gears connected with a main drive shaft 9. In the form shown (Figure 9) these gears comprise a gear 10 fixed on said shaft and meshing with an idler gear ll, which in turn meshes with a gear 12 fixed to the lower end of a short shaft 13; Upon the upper end of shaft 13 is fixed another larger gear 14. The gear'14 meshes with a gear 15 which is suitably secured to the wheel 8, whereby, whenfthe shaft 9 is driven, the wheel 8 will be rotated at a speed determinable by the respective gear ratios employed, and which, of course, may be varied as desired by simply changing-the gear 14. As shown in Figure 9, the gears 1112-14 are mounted on an ad justable frame or arm 16, which is capable of being swung so as to permit of the substitution of a gear of any appropriate size in place of the gear 14. In the form shown,

this arm 16 when properly adjusted, is locked .in position by any suitable means, such as a clamping bolt 17.

Mounted at intervals around the wheel 8 arevertically arranged tubular guides 18 for the so called work carriers. to Figures4 and 5 it will be seen that each work carrier comprises a hollow spindle 19, which is mounted to rotate freely in a sleeve 20. This sleeve is capable of movement up and down in the tubular guide 18 carrying with it at the same time the spindle 19. The back of each tubular guide 18 is vertically slotted, and projecting through this slot is a lug 21 fixed on the back of the sleeve 20.

' 22 is a roller on theend of the lug 21, which roller makes engagement with the camring 7 as hereinafter described, and by. which the sleeve 20 and spindle 19 may be raised and lowered.

The spindle 19 carries at its lower end the work gripping means for holding the articles passing through the machine compriseswhat This foot is in I will term a presser foot 27. the form of a blade carried at the lower end of a rod 28 which passes upwardly through the spindle 19. Referring to Figure '5 it will .be seen that this rod is pressed downwardly by means of a spring 29. The limit'of downward movement is determined by a stop pin 30, moving in the slotted'upper end of an extension 31 at the upper end of the sleeve 19.

Referring The rod 28 is provided with a suitable head I piece 32 carrying a roller 33, which latter, at certain times, rides onand is held up by a track so that the presser foot 27., will be held I against downward movement at such times even though the spindle 19 is depressed. The

presser foot-27, the fingers 23-23 and hooks 25-25 of the article grippers are preferably enameled, so that neither the coating material nor the coated articles will tend to adhere thereto. The presser foot 27 is preferably detachably connected to the rod 28, as 7 by a suitable coupling 34, which preferably is v provided with a flanged head 35' serving to protect the joint between the lower end of the rod 28 and .said coupling. It will be observed that the end of the presser'foot 27 is" bent out ofline with the rod 28,'the purpose of which will be later explained. By making hereinafter described. 37 is a mutilated gear fixed on the spindle 19 just below the wheel 36. This mutilated gear-co-acts with a seg- I mental gear 38 (see Figure 16), which is yieldingly'mounted on suitable guidestuds 39- 39 for fore and aft movement. The gear 38 is projected forwardly by a suitable spring 40 so as to stand slightly in the path of travel of the mutilated gear 37. It follows that whensaid gears engage, the mutilated gear will be rotated until its mutilated or flat portion faces the teeth of thesegmental gear 38, which at that moment springs out and checks the further rotation of the spindle 19, stopping it in a predetermined position, for the purposes later described.

41 is a relatively small reservoiror tank, in'advance of the main reservoir 3 (see Figure 8), and in the path of travel of the articles to be coated. When tin is to be applied as a. coating material it is the practice to first apply to each article an appropriate flux, such as sal ammoniac, and to that end the tank 41 is supplied with a quantity of said flux in solution, which is automatically maintained at aproper level, as by an air-sealed inverted supply bottle 42, (Figure 15) so associated with the reservoir 41 that, as added flux is required in said tank, a supply thereof will automatically flow in from .the source 42. It i important, in the preferred embodi ment of this invention. to maintain an appropriateilevel so'that enough. and yet not too much, of, the flux will be applied to the article to .be coated preparatory to its being immorsed in the molten tin or the like. Referring to Figures 8 and 7. respectively. the course of travel of a single article to be plated is there indicated. The severalillusseen that a carrierwith a spoon therein first approaches the tank 41, but as et the spoon has not been positively gripped y the presser foot. During this first'movement the roller 33 rides along the track 43, and the roller 22 at the back of the carrier supporting sleeve 20 moves along the straight portion 44 of the cam groove in the cam rin 7. When the roller 22 reaches the upward bend of the groove, the sleeve 20 and rotatable spindle 19; are lifted to a sufficient extent to cause the article to come into contact with the presser foot'27. At this point the roller 33 leaves the track 43 so that after passing the high spot 45 ofthe cam, the roller will ride down an incline to a lower level 46 moving the spindle 19 and rod 28 bodily down to a level to dip the article 26 into the flux solution to the desired extent. As the work carrier proceeds forwardly it again encounters an upward incline and high portion47 of the cam groove, which serves to lift the Work carrier and the article out of the flux. Proceeding forwardly from here the roller 22 rides down an inclined portion 48 of the cam so as to cause the work carrier to immerse the article in the coating material within the reservoir 3. While the article is being passed through this coating material in the reservoir 3 it is preferably agitated up and down, this movement being effected by undulations 49-49 in the cam groove. lVhen the article has been immersed for a sufficient period it is lifted above the level of the coating material by an upward incline 50, (see Figure 7 As it proceeds forwardly from this point and-before it leaves the region of the reservoir, the work carrier and the article carried thereby is given a rapid whirling motion so as to throw off by centrifugal force all surplus material thus leaving the surface smooth and bright. This surplus material falls back into the reservoir and is saved. The whirling motion also serves by centrifugal action to throw off such material from thefingers 23-23 and the presser foot 27 which latter should be kept reasonably free thereof for effective operation. The means by which this rapid rotary or whirling action is produced will be later described. Since the surplus material is removed by centrifugal action, the surface of the article is left smooth and unriffled.

After this rotation the work carrier is lifted still further by the cam incline 51 so as to clear the reservoir. As the carrier proceeds forwardly the mutilated gear 37 encounters the segmental gear 8, which operates to line up the article properly for discharge and at the same time correctly position theroller 33 so that it will properly'encounter its track when reached. As the car rier continues along beyond the alignlng mechanism the roller 33 againcomes over -the track 43, whereafter the roller 22 encounters a depression 52 in the cam'grove, which forces the spindle 19 downwardly so as to move the hooks 25-25 away from the presser foot 27, which is now held elevated by the track 43. 'On this movement the hooks 25-25 descend sufficiently far to cause the then coated article to momentaril engage cast-off inclines 53-53, which dis odge the article from the hooks, which article then slides down said-inclines by gravity (see Figure 10) to a conveyor belt 54, which latter is driven by any suitable means at a proper speed to remove the finished articles successively from the machine. The cast off inclines 53-53 are preferably relatively thin blades attached to a yoke, which latter is mounted so as to be capable of oscillation.

In the form shown the yoke is rotatably mounted on a shaft or pin supported from the main frame and a spring 53 urges the yoke against the stop pin 53 so as to position the inclined fingers 53-53 at the proper points. If, during the act of discharging a coated article, the forwardly moving gripping means or other part should contact with the cast off inclines 53-53, the latter, being resiliently held by the spring 53, will yield and prevent any damage to the parts. The

parts are preferably so timed that'the period from the moment the spoon leaves the molten metal to the moment it is dislodged from the hooks will not be long enough to allow the coating to set to such an extent as to cause the spoon to stick to said hooks. Said period, on the other hand must be long enough so that the surface coating will be sufficiently set to resist injury when it is discharged. The

belt 54 is preferably made from what is termed card clothing. with the wire ends directed outwardly so that the finished articles will be supported on several fine points which will not injure the surface even though it'is not yet completely set.

. The means for whirling the spindle and'the coated articles comprises two power-driven rapidly rotating friction wheels 55-56 (Figure 13) These may be driven from any source of power, such a an electric motor 57, mounted on a suitable framework 58 carried on top of the central post 6. wheel 55 is mounted at the lower end of a shaft, upon the upper end of which is mount A spring 61 serves to swing said arms toward lit) The friction engaging suitable shoulders on the main frame 58, on which said arms are pivoted,

whereby the .normal spacing of said wheels 56, may be varied at will.. 64:6566 are idler pulleys. 67 is a belt'which is driven by the motor 57, and which belt runs around the several pulleys aforesaid, so as to rotate the same in the direction indicatedv by the arrows in Figure 13. The' friction wheels 5556 are positioned in the path of movement of. the wheel 36 and are so spaced that the said wheel 36 must pass between and engage the same in the course of its travel. Manifestly, the moment the spindle wheel 36 encounters these rapidly revolving friction wheels, the work-carrying spindle and the freshly coated article will be given a rapid whirling movement, soas to throw off all surplus coating material as before described.

I hinged to the opposite edges of the reservoir.

The adjacent edges of the opposite shield sections are separated sufficiently far to provide a clearance passage through which the work carrying spindles may pass. By this means any noxious gases generated are con: fined, so that, the great portion, if not all, of these gases maybe drawn off by a suitable exhamster and delivered at a point remote from the machine and the room in which it is installed. In Figure 20 I have shown an exhauster in the form of a flue 69, which is in connection with that part of the reservoir directly above the surface of the molten material, and this in turn may be connected with any suitable form of suction means such as an ordinary chimney or stack.

In Figure 19 I'have illustrated a receptacle 7 0 for holding suitable material, such as resin,

which may be employed to facilitate a tinning operation; This receptacle may have a portion 71 projecting down into the molten metal,

so as to keep the resin in a liquid state. 72

represents an outlet by which the liquid resin vmay be delivered to the molten metal.

72 represents a valve for controlling the size of said outlet, to regulate-the feed of this material.

In order that productionmay be increased, it is desirable tohasten the cooling of the plated articles, and artifical cooling means In the preferred form a. minimum surface of molten metal is exposed to the air. In the present disclosure, pads 8081 are positioned within the reservoir 3 and float upon the surface of the molten metal. These pads are preferably -hollow metal sections filled with insulating material, such asasbestos, as in- 'drcated at 82.

The pads 80-81 may be spaced apart by suitable cross braces 8384. It should be noted that theswbraces hold the pads separated so that the articles to be coated may pass therebetween anddip in the molten metal. WVhen' the machine is in operation, the pads 81 arethe only ones in use, butwhen the machine is stopped for a protracted period, as forinstance, over night, other .pads 8586, which may be of the same general construction as those heretofore described, are placed within the reservoir and substantially cover the surface of the molten metal. It will be evident that with at least a large portion of the surface of molten'i'netal covered, oxidation or formation of dross will be reduced to a minimum. It'will likewise be apparent that with the reservoir itself insulated and with the surface of the molten metal covered with insulating pads, radiation will be reduced, and but little energy will be required to maintain the coating material in a molten state.

In the operation of the machine, it may be desirable to state that only a single attendant coating material in the reservoir, wherein it is rapidly agitated up and down. This action guarantees that all portions of the surface of the article will be covered, and is also useful in so agitating the contents of the reservoir as to prevent, in the case of molten material, an accumulation of dross on the surface. The article is then withdrawn from the bath. Before it leaves the zone of the reservoir 3 it is rapidly whirled, so that the surplus material isd-ischarged therefrom by centrifugal force and runs back into the molten metal within said reservoir and is saved. The article is then transferred to the aligning mechanism and properly aligned for release and discharge. When the article reaches the conveyor belt it is automatically released and falls by its own weight onto said belt, by which it is removed from the region of the oncoming finished articles.

In carrying out the .process of tinning in 'skill and is a relatively slow process.

its'preferred form, a large number of the blanks to be coated are dipped or immersed in molten metal while being held in a wire basket, so as to-give them a rough coating of tin, which is allowed to solidify. No attempt is made to secure a uniform coatin nor to produce a finished article by this pre iminary step. These blanks or articles having been thus previously prepared with an initial rough coating, are then fed to the machine, and, in passing through the 'molten'metal reservoir as above described, the preliminary or rough coating is melted. When the article is removed from the molten metal, it is thoroughly coated and the surplus metal is then thrown off or removed as heretofore described. It usually happens that so much tin or other coating material applied during the preliminary dipping of the articles, is removed in the spinning operation, that the surplus thus saved actually increases the quantity inthemolten metal reservoir, so that the surplus has to be ladled out.

By the use of this machine, great economies are effected in the saving ofmaterial, in that the onlymaterial escaping from the machine is that actually deposited on the surface of the article to be coated. Again, a great saving in labor is effected, as the machine has a capacity equal to'that of several skilled operatives and requires the attention of only one operative who need not necessarily be skilled in-the art of tinning.

In the ordinary processof hand 'tinning a skilled operative is obliged to handle each.

article separately in a pair of tongs. The

} article is first hand dipped and agitated for a sufficient period in a mass of molten tin. It is then withdrawn and the operative man ually shakes off the surplus tin which is usu ally deposited on the floor, forming a pile of/ waste. To shake off all the surplus material by hand so a'sto leave only a smooth, finished surface, requires 1 long practice and miigh y the use of my machine, all-this work is performed Without requiring the services of a skilled artisan, the coated articles possess great uniformity of finish; the capacit of the machine is equal to that of several skllled workmen; and the waste of material is wholly eliminated.

I claim:

1. A machine for coating articles comprising a tank for containing coating material, an article carrier, means for moving said carrier to advance an article to be coated through said material, means for moving said article up and down while in said material, and means for whirling said carrier and the arti'cle carried thereby after the latter is withdrawn from said material to remove surplus material therefrom by centrifugal action.

2. A machine for coating articles comprising a tank for containing coating mater1al, an

article carrier, means for'moving said carrier to advance an article to be coated through said material, means for moving saidarticle up and down while in said material, means for whirling said carrier and the article car:

ried thereby after the latter is withdrawn from -said material to remove surplus material therefrom by centrifugal action, and

heating means for said'tank.

4. A machine for coating articles'comprising a. tank for containing coating'material, an article carrier, means for moving said carrier to advance an article to be coated through said material, means for moving said article up and down while in said material,

and means for whirling said'carrier and the article carried thereby for the purpose described when the latter is withdrawn from said material to remove surplus material therefrom by centrifugal action, and electric heating means for said tank.

5. A machine for coating articles comprising a tank for containing coating material, an article carrier, means for moving said car rier to advance an article to be coated through said material, means for moving said article upand down while in said material, means for whirling said carrier and the article carried thereby after the latter is withdrawn from said material to remove surplus material therefrom by centrifugal action, heating means for sand tank, said means comprising cupped recesses in the bottom-of the tank with electric heating elements mounted there- 6. A machine for coating articles comprising a tank for containing coating material, an article carrier, means for moving said carrier to advance an article to be coated through said material, meansfor moving said article up and down while in said material, means for whirling said carrier and the article carrial therefrom by centrifugal action, said means for advancing said article carrier comprising a rotatable wheel, with means carried thereby for supporting a plurality of such carriers. l

7. A machine for coating articles comprising a tank for containing coating material, an article carrier, awheel support therefor,

' means for moving said carrier to advance an article to be coated through said material, means for moving said article up and down I thelarticles up 1o means for moving said article up and down while insaid material, means for whirling said carrier and the article. carried thereby "after the latter is'withdrawn from said mat'er-ial to remove surplus material therefrom by centr fugal action, said means for moving the "articles up and down comprising a cam ring cioiuceiitrio with said wheel, means for jcheckin'g"thel whirling movement of said "spindle and' thejarticle carried thereby for e purposeipjfali-gning said'parts. v 9.-' .A mach" foracoating articles comprising a tank 'for -containin coating material,

Iried thereby after the latter? is withdrawn" .from said material to remove surplus material therefrom by centrifugal action, a

an article carrier, means or moving said carri-er to advance. anarticleitdbe coated through I said material, mea'nslfor moving saidarticle up and down while in said material, means for'whirhng said carrier and the art cle carmechanically operatedarticle gripper on-said carrier with means for opening and closing the same, and means for mechanically disengaging the article from said gripper when the latter is open. c

. 10. A machine for coating articles comprising a tank for containing coating material, an article carrier, means for moving said carrier to advance an article to be coated through said material, means for moving said --article up and down while in said material,

means for whirling said carrier and the article carried thereby after the latter is withdrawn from said material to remove surplus material therefrom by centrifugal action, a mechanically operated'article gripper on said carrier with means for opening and closing the same,'means for mechanically disengaging the article from said gripper when the latter is open and for conveying each finished article away from each succeeding'finished article.

11. A machine for coating articles com prising a tank for containing coatinghnaterial, a carrier for the article to be coated, means for advancing said carrier and. for moving the same up and down to cause the article to be treated to be passed through the coatinz'material in the tank, means for whirlby after it has been withdrawn from said material to remove surplus material therefrom by centrifugal action and before it leaves the region of said tank.

ing said carrier and the article carried there- 12. A machine for coating articles comprising a tank for containing coating material, a carrier for the article to be coated, means'for advancing said carrier and for moving the same up and down to cause the article to be treated to be passed through the coating materialin the tank, means for whirling said carrier and the article carried thereby after it has been withdrawn from said ma terial and before it leaves the region of said tank, said carrier including a tubular spindle carrying one part of a. mechanical article gripper, "a rod passing through said spindle and carrying a complementary part of said article gripper, means for holding said rod against downward movement at certain times when said tubular spindle is depressed to open said gripper, said rod moving up and down with said tubular spindle at other times when said gripper. isclosed.

13. A machine for coatmg articles with metal comprising a tank for holding such metal, means for heating such metal to a be-coat-ed and for immersing it-in said molten metal and withdrawing it therefrom and for mechanically whirling the coated article to throw off by centrifugal action any excess of said metal so as to leave af-substantially smooth andevenly finished surface coating on said article, and means for'mechanically releasing and removing said article from said gripping means.

14. A machine f i coatinglarticles with -metal comprising a. tank for holding such metal, means for heating such metal to a molten state, means for gripping an article to be coated and for immersing it injsaid molten metal and withdrawing it therefrom and for mechanically whirling thecoated article to molten state, means for gripping an article to throw ofl by centrifugal action any excess of said metal so as to leave a substantially smooth and evenly finished surface coating on said article, means for mechanically releasing and removing said article from said gripping means, with means for conveying each article removed from said gripper out of the path of the next finished article.

15. A machine for coating articles:with metal comprising a tank for holding such metal and, means for heating the same to a molten state, another tank for holding'a flux for treating the articles preparatory to the coating operation, means for mechanically gripping an article to be coated and said means being movable for dipping said article into said fluxand thereafter immersing said article in said molten metal and thereafter withdrawing it therefrom and for rapidly whirling the then coated article to throw off 'IDOVGIIIGIlt to said parts at certain times to by centrifugal action any excess'of metal so as to-leave a substantially smooth evenly tinished surface coating on said article, with means for thereafter freeing said article from said gripping device before it shall adhere thereto.

16. A machine for coating articles with metal comprising a tank for holding such metal and means for heating the same to a molten state, another tank for holding a flux for treating the articles preparatory to the coating operation and means for maintaining said flux at the desired level in said tank, means for mechanicallygripping an article to be coated and said means being movable for dipipng said article into said flux and thereafter immersing said article in said molten metal and thereafter withdrawing it therefrom and for rapidly whirling the then coated article to throw off by centrifugal action any exccssof metal so as to leave a substantially smooth evenly finished surface coating on said article, with means for thereafter freeing said article frolri saidgripping device before it shall adhere thereto.

17 In a machine for coating articles with molten metal, a tank for containing molten metal, electric heating means associated therewith for melting said metal and maintaining the same in a molten state, shields for said tank covering a substantial portion thereof and an-exhauster having a suction opening above and adjacent tothefle-veljof the molten metal in said tank,.a receptacle for containing resin or the like, saidheceptacle being arranged adjacent to said tank and above the level of molten metal. therein, with a discharge outlet leading thereto.

18. In a machine for tinning articles, 'a receptacle for holding molten tin, a work-carrier for conveying articles therethrough, means for moving said work-carrier comprising a power driven-wheel, a carrier guide mounted thereon, a sleeve in which the workcarrier rotates said sleeve being mounted in said guide, said guide having a vertical slot therein, a lug on the sleeve projecting through said slot, a cam wheel adjacent to said sleeve and cooperating with said lug to raise and lower the work-carrier.

19.- In a tinning machine of the character described, a Work-carrier comprising a r0 I tatably mounted tubular sleeve having a work gripping device at-its lower end, a rod'within said sleeve and rotatable therewith, said parts being longitudinally movable independently of each other, both of said parts being bodily rotatable, said rod carrying a complementary gripping means co-acting with the gripping means on said tubular spindle, means for im' parting independent relative longitudinal open and close the gripping means, and means for lmpartmg a rapid rotary movement to said parts to whirl an article carried thereby at a certain time. I

20. In a tinning machine of the character described, a work-carrier comprising a rotat ably mounted tubular sleeve having a work gripplng device at its lower end, a rod within said sleeve and rotatable therewith, said parts at a certain time, and means cooperating with said carrier to move the two parts thereof forward through the machine and to impart a bodily up and down movement to said parts" at certaintimes during said forward move,- mnt. i

21. The method of coating an article with tin, which comprises first applying a'rough' coating of tin to the article, permitting said coating to solidify, then immersing the article in a bath of molten tin to melt the rough coating, then. removing the same from said bath, 'and then rota-ting the article at a high velocity about an axis within itself to throw off by centrifugal action the surplus coating of metal, returning said material to said bath. 22.. The method of coating an article with metal which comprises, applying a coating of molten metal to the article, then rotating each article about an axis within itself at a high velocity for throwing off by centrifugal actionthe surplus -of molten metal, then permittlngthe coating to at least partially solidify, and then depositing the article for cooling purposes on sharp points to prevent i marring of the coating.

23. The method of forming a metal coated article which comprises, applying a coating of molten metal to the article, then removing the excessfcoating of molten metal so as to leave a finished surface, then permittingthe coating to at least partially solidify, and then depositing the article on a series of sharp projections whereby the coating of molten metal,

if not entirely solidified, will not be marred.

24. In an apparatus of the character described, a reservoir for'holding molten metal, including a trough-shaped container, having a curved work passage therethrough and curved cover plates for said container mounted at opposite sides.of,said trough and projcting toward other with means to hold said 'plates' spaced apart to form a curved track passage for the free travel of a tool therebetween, at least one of said cover plates being movable.

25'. In a machine for coating articles with molten metal. a. .reservolr fpr containing mol- 'ten metal, means for heating metal in said reservoir and maintaining the same in a a said conveyor means.

molten state, and hollow metallic pads floating on the surface of the molten metal in said reservoir, said hollow pads being filled with insulating materiahand spacing means for said pads for definitely spacing the same to form a track passage for a tool.

26. In a'n achine for coating articles with molten metal, a reservoir forcontaining molten metal, a rotatable work gripper for holding an article and dipping it in the molten I-metal, movable conveyor means for receiving the article from the work and-means for cooling the article jVhllB on ripper after the same has been dipped in tie molten metal,

' "27. In a machine for coating articles with molten metal, areservoir for containing molten metal, a rotatable article gripper for holding an article and dipping the latter in the molten metal, means for directing acurrent of air on to said article While the latter is held by said gripper, a conveyor on which the art-iele'is deposited when released by said gripper, and means for cooling the article while on said conveyor.

DARWIN G. GRISWOLD. 

